I think that it would be faster and easier to learn to knit in the round for these. Knitting in the round is great to know, lots of things are faster and easier in the round. That said, there are owl cable patterns for flat knitting so you could try incorporating one of them into flat knit mitts. I strongly suggest that you try knitting in the round.
Cheating is an option. . . . Cheaters never win and winners never cheat, but smart knitters who want to retain an iota of sanity do, cheerfully. ~~Kory Stamper